1. Field of the Invention
This invention provides a connector for a flexible member, such as a chain or strand, used to attach jewelry to the person.
2. Description of the Related Art
There are a large number of different types of connectors which have been developed in response to the needs of this application. These include snaps, threaded connectors, interlocking connectors, gripping connectors and various combinations of these arrangements. Some of these connectors are quite complicated and all of them have at least one moving part.
It would be desirable if the connection apparatus could be simplified and not require any complicated or moving parts. In all of these connectors one part must be held in one hand while the other part is held in the other hand to make or break a connection, typically by threading one element through or into another. Because of their small size, attaching these connectors is quite difficult. It would also be desirable if the process to connect or disconnect the parts was made easier, and if the connection process could include a means for aligning the parts to be connected. Using any of the present connectors is particularly difficult when they are used to attach a bracelet because it is impossible to use two hands to connect or disconnect a bracelet around ones own wrist. It would be particularly desirable therefore if the connection and disconnection process for a connector used with a bracelet could be accomplished using only the free hand.
The primary advantages of the connector are: it has only two simple parts, it is connected and disconnected only by forcing the parts together or apart by a predetermined force acting against a predetermined resistance, it obtains the predetermined resistance merely by flexion or compression of a part, it has guide means for aligning the parts to be connected, and in one embodiment it can be connected and disconnected using only one hand.
I have observed that the connected ends of flexible members under tension always extend outward directly opposite to each other, and always have the same predetermined orientation with respect to their connector. The orientation of the ends of the flexible member under tension relative to the connector is determined by the location of the attachment point of the flexible member ends to the connector. The present invention utilizes that observation. The essence of this invention is that the connection can be made or broken only by a force which is perpendicular to the predetermined orientation of the flexible member ends under tension. Opposed tension forces, regardless of their magnitude, cannot separate the connector parts with this arrangement, because any forces applied by the flexible member ends will always be perpendicular to the force required for disconnection.
With this arrangement the connector must be made strong enough to withstand any tension forces applied by the opposed ends of a flexible member, however, providing a secure connection with this arrangement requires only that the force required to attach or release the connection be greater than any perpendicular forces which may act upon the connector. Since, as noted above, the perpendicular forces exclude the tension forces applied by the ends of the flexible member, they essentially only include such forces as gravity acting upon one unsupported member, and different acceleration forces applied to the two ends of the flexible member. Since jewelry uses small connectors with little weight, which do not experience acceleration forces, these perpendicular forces are quite small. Consequently the predetermined perpendicular force required to connect or disconnect the connector, while still providing a secure connection, can also be made quite small.
The preferred embodiments of the invention all have a connector with only two parts, namely a receiver and an insert, which are connected to opposite ends of a flexible member. The receiver has at least one projection which forms an enclosure sized to enclose at least a portion of the insert. The enclosure has an opening oriented essentially perpendicular to the orientation of the connected flexible member""s opposed ends under tension. The opening and the enclosed portion of the insert are sized and arranged such that a predetermined force is required to pass the enclosed portion of the insert through the opening. This required predetermined force can be obtained by having a flexible opening, sized to restrict the passage of the insert, or by having a rigid restricted opening and a compressible insert. This required force can also be obtained by having both a restricted opening with a flexible opening and a compressible insert.
The parts are connected by forcing the insert through the opening into the enclosure. A guide extending outwardly from the opening centers the insert on the opening to aid in connecting the parts. To disconnect the parts, since tension on the flexible member ends cannot pull the insert through the opening, the insert must be pulled outward by hand in a direction perpendicular to the orientation of connected flexible members under tension.
In one embodiment the insert is essentially spherical, the enclosure is hollow and hemispherical, and the opening is essentially circular.
In another embodiment, the insert is cylindrical, the enclosure is essentially one-half of the cross-section of a hollow cylinder, and the opening is essentially rectangular. With this arrangement the insert and receiver must be aligned along their cylindrical axis for the insert to enter the opening.
In yet another embodiment, the insert and receiver are both essentially planar and disk shaped, with an enclosure defining a planar disk shaped volume parallel to the receiver planar surface, and an opening which is essentially perpendicular to the receiver planar surface. With this arrangement the insert and receiver must be aligned along both planar axes in order for the insert to be contained by the enclosure. In this embodiment, when one of the receiver""s planar sides is placed upon an essentially horizontal surface, the receiver will remain in that attitude with the opening either upward or downward. This stability permits using only one hand to connect and disconnect the connector, as will be described later in detail.
The operations for connecting or disconnecting the insert and receiver require only that one part be forced a small distance into or out of the other part. This simple operation, the fact that the force required can be made quite small, and the centering guide makes connecting and disconnecting the parts quite easy.